This invention relates generally to sunroof assemblies for automotive vehicles and specifically to a dual sunroof assembly and a control system for operating same.
It is common knowledge to provide a single sunroof within a stationary roof of an automotive vehicle. These traditional sunroofs typically employ a transparent glass pane slidable from a covering position, somewhat flush to the roof, to a retracted position, which allows sunlight and ventilation access through an opening within the roof. Another traditional sunroof construction provides a transparent glass pane which is tiltable from a closed position to a pivoted venting position. This allows air from within the vehicle to pass through an opening created between the vented pane and the roof. A single sliding interior sunshade has also been employed with various of these sunroofs. Such sunshades are typically horizontally oriented and slidably movable to expose or cover a sunroof.
It is also known by those in the automotive industry to provide a pivotable wind deflector in front of a sliding spoiler-type sunroof. Such a construction is disclosed within U.S. Pat. No. 4,659,140 entitled "Vehicle Roof" which issued to Fuerst et al. on Apr. 21, 1987, and U.S. Pat. No., 5,069,501 entitled "Spoiler Control Mechanism" which issued to Baldwin et al. on Dec. 3, 1991, the disclosures of which are incorporated by reference herewithin. However, wind deflectors of this type merely pivot and do not slide to a retracted position. Thus, such a wind deflector limits the roof opening that would otherwise be disposed above the front seat occupants.
U.S. Pat. No. 4,786,102 entitled "Sun Roof Apparatus of Vehicle Roof" which issued to Sakamoto et al. on Nov. 22, 1988, attempts to further increase the effective roof opening, especially above the front seat, by employing a pair of movable covering panels. This device provides a rear cover panel which is detachably removable such that a front cover panel can be rearwardly slid. Provisions are also made for manually mounting the removed rear cover panel upon the retracted front cover panel. However, this system appears ungainly to operate especially while driving the automobile.
U.S. Pat. No. 5,197,779 entitled "Power Sliding Sunroof" which issued to Mizuno et al. on Mar. 30, 1993, discloses a pair of slidable sunroofs mounted in tracks on top of a stationary roof. The disclosure of this patent is incorporated by reference herewithin. However, this non-flush roof system is aesthetically prominent, is prone to excessive wind noise during vehicle driving and will cause excessive aerodynamic drag in all operating positions.
Various manual and motorized driving mechanisms have been used in combination with the aforementioned sunroofs. For motorized actuation, various electrical circuits have been employed to control operation of the operating mechanisms. One such circuit and switch for energizing a motorized drive is disclosed within U.S. Pat. No. 4,556,835 entitled "Operating Mechanism for Movable Parts, Especially for Sliding Roofs and Sliding/Lifting Roofs" which issued to Vogel et al. on Dec. 3, 1985, and is incorporated by reference herewithin. Another such circuit is discussed within UK Patent Application GB 2077461 entitled "Operating Mechanism for Tilting and Sliding Roof Panels." These circuits and switches, however, do not provide a means for controlling a pair of movable panes, a pair of movable sunshades, or any combination thereof.
In accordance with the present invention, the preferred embodiment of a sunroof assembly of an automotive vehicle employs dual sunroof panes, a pair of movable sunshades and a control system for operating the function thereof. In one aspect of the present invention, a sunroof assembly provides a substantially transparent front pane which is slidable from a covering position to a retracted position and a substantially transparent rear pane movable from a covering position to an open position. At least one of the panes is retractable below a stationary roof of the automotive vehicle. In another aspect of the present invention, a sunroof assembly provides a pair of substantially transparent panes in combination with a substantial opaque front sunshade and a substantially opaque rear sunshade. The sunshades are movable from a functional position to a stowed position. In a further aspect of the present invention, a control system provides an electric switch assembly, electrical circuit and software for operating the panes and sunshades. A unique sunshade guide rail system is also provided. The sunroof assembly of the present invention further employs a drain trough attached to a movable pane.
The sunroof assembly of the present invention provides many advantages over conventional sunroof constructions. For example, the present invention sunroof assembly allows for an increased roof opening when the panes are retracted and an increased daylight opening (or glass coverage space) when the panes are in a covering position. The sunroof assembly of the present invention is also easily operable to a fully or partially retracted position even while the vehicle is being driven. The present invention further employs a unique arrangement for stowing a pair of panes and sunshades in order to minimize headroom intrusion below the roof surface without increasing aerodynamic drag, wind noise or unsightliness when the panes are in their covering and unretracted positions. The control system of the present invention is advantageous over conventional systems by providing an easily accessible and operable switch, circuit and software for facilitating easy driver use which is also quite cost effective and efficiently constructed. The present invention control system prevents inadvertent collisions between panes and sunshades. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.